php - Managing IDs in mySQL

I have a users table in my database. The structure is this:

fam_id
user
name
username

The fam_id is primary with AUTO_INCREMENT and goes like 1, 2, 3.... The user is the telegram's userID, which I use to identify the users. The name and the username are the name and the username in telegram.

Ok, everything is ok, I insert suer, name, username, Mysql generates the fam_id. But now I need to give to some users the same fam_id.

So my question is: Is there a way to generate a casual id, which mySQL can't give to anyone else, but that can be changed by me to another's user fam_id, having so to users with the same fam_id?

I simply tried by making fam_id AUTO_INCREMENT and changing with UPDATE, but it doesn't work.

Solution:

Well, because fam_id is a primary key and it's AUTO_INCREMENT, you can not and should not change it. If you really, really need this funtionality you described, you can add a column, like my_id. Then at your implementation, after you inseted a new user... res = MySQL.query(INSERT INTO users ... ) ... MySQL returns a result set. Have a look at it and do something like this: temp = res[0].fam_id MySQL.query(UPDATE users SET my_id = temp WHERE fam_id = temp)

PS: This is js syntax, but I'm sure php has something similar